Therapeutic drug monitoring (TDM) is the quantification and interpretation of drug concentrations in blood to optimize pharmacotherapy. It considers the interindividual variability of pharmacokinetics and thus enables personalized pharmacotherapy. In psychiatry and neurology, patient populations that may particularly benefit from TDM are children and adolescents, pregnant women, elderly patients, individuals with intellectual disabilities, patients with substance abuse disorders, forensic psychiatric patients or patients with known or suspected pharmacokinetic abnormalities. Non-response at therapeutic doses, uncertain drug adherence, suboptimal tolerability, or pharmacokinetic drug-drug interactions are typical indications for TDM. However, the potential benefits of TDM to optimize pharmacotherapy can only be obtained if the method is adequately integrated in the clinical treatment process. To supply treating physicians and laboratories with valid information on TDM, the TDM task force of the Arbeitsgemeinschaft für Neuropsychopharmakologie und Pharmakopsychiatrie (AGNP) issued their first guidelines for TDM in psychiatry in 2004. After an update in 2011, it was time for the next update. Following the new guidelines holds the potential to improve neuropsychopharmacotherapy, accelerate the recovery of many patients, and reduce health care costs.

than 5 decades [ 521 , 522 ] , growing evidence suggests that improving the way the available medications are administered may bring substantial benefi t to patients [ 45 ] . Evidence-based guidelines for optimum treatment have been published during the last decade [ 23 , 46 , 101 , 204 , 205 , 221 , 234 , 254 , 276 , 284 , 582 , 585 ,748]. A valuable tool for tailoring the dosage of the prescribed medication(s) to the individual characteristics of a patient is therapeutic drug monitoring (TDM). The major reason to use TDM for the guidance of psychopharmacotherapy is the Introduction ▼ In psychiatry, around 130 drugs are now available which have been detected and developed during the last 60 years [ 54 ] . These drugs are eff ective and essential for the treatment of many psychiatric disorders and symptoms. Despite enormous medical and economic benefi ts, however, therapeutic outcomes are still far from satis factory for many patients [ 5 , 6 , 396 , 661 ] . Therefore, after having focused clinical research on the development of new drugs during more Therefore the TDM consensus guidelines were updated and extended to 128 neuropsychiatric drugs. 4 levels of recommendation for using TDM were defi ned ranging from "strongly recommended" to "potentially useful". Evidence-based "therapeutic reference ranges" and "dose related reference ranges" were elaborated after an extensive literature search and a structured internal review process. A "laboratory alert level" was introduced, i. e., a plasma level at or above which the laboratory should immediately inform the treating physician. Supportive information such as cytochrome P450 substrateand inhibitor properties of medications, normal ranges of ratios of concentrations of drug metabolite to parent drug and recommendations for the interpretative services are given. Recommendations when to combine TDM with pharmacogenetic tests are also provided. Following the guidelines will help to improve the outcomes of psychopharmacotherapy of many patients especially in case of pharmacokinetic problems. Thereby, one should never forget that TDM is an interdisciplinary task that sometimes requires the respectful discussion of apparently discrepant data so that, ultimately, the patient can profi t from such a joint eff ort. This document was downloaded for personal use only. Unauthorized distribution is strictly prohibited. considerable interindividual variability in the pharmacokinetic properties of the patient [ 524 , 526 ] . At the very same dose, a more than 20-fold interindividual variation in the medication's steady state concentration in the body may result, as patients diff er in their ability to absorb, distribute, metabolize and excrete drugs due to concurrent disease, age, concomitant medication or genetic peculiarities [ 61 , 94 , 310 , 311 , 334 , 335 , 374 ] . Diff erent formulations of the same medication may also infl uence the degree and temporal pattern of absorption and, hence, medication concentrations in the body. TDM uses the quantification of drug concent...

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The present findings indicate that estradiol may have specific antipsychotic-like effects on the symptoms of schizophrenia. Thus further investigation into the therapeutic effect of estrogen may be worthwhile.

The present guidelines for TDM application for neuropsychiatric agents aim to assist clinicians in enhancing safety and efficacy of treatment.

The atypical antipsychotic drug amisulpride is a benzamide with specific antagonistic properties, which target dopamine D 2 and D 3 receptors, preferentially in the limbic system. Amisulpride is readily absorbed from the gastrointestinal tract, distributed to all body systems with little binding to plasma proteins. Elimination occurs mainly through the kidneys as unchanged drug. In contrast, hepatic metabolism is of minor significance and primarily yields two inactive metabolites. Very little is known about the plasma concentrations of amisulpride in patients at varying oral doses or about clinically relevant interactions with co-medication. The aim of the present investigation was to elucidate the factors, which affect amisulpride levels in schizophrenic patients. The plasma amisulpride levels of 85 patients with schizophrenia or schizoaffective disorder (mean age: 34.0 F 11.4 years; 40 women, 45 men) were assessed by high-performance liquid chromatography (HPLC) with fluorometric detection. The average daily dose of amisulpride was 772.3 mg (S.D. 346.7 mg) and the mean amisulpride plasma concentration was 424.4 ng/ml (S.D. 292.8 ng/ml). The interindividual variance of the amisulpride plasma concentration was high; furthermore, the plasma concentration increased linearly with the daily oral dose (r = 0.50, p < 0.001). Age and gender showed a significant effect on the dose-corrected amisulpride plasma concentrations -older patients and women had higher dose-corrected amisulpride plasma concentrations than younger patients and men. However, cigarette consumption had no effect on the amisulpride plasma concentrations. Regarding co-medication with lithium and/or clozapine, significantly higher amisulpride plasma concentrations were found as compared to monotherapy, whereas other co-medications such as benzodiazepines and various conventional antipsychotics had no effect on the amisulpride plasma concentrations. The results, the possible pathomechanisms and the clinical relevance are discussed. The findings need to be confirmed in larger patient samples and with a wider range of co-medications. D

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